I am planning on trying this next week.
You can get the Carbon FIber at any serious hobby shop that does RC planes and the like.
You can cut it with a Zona saw or other small razor saw. It glues extremely well with cyanoacrylate (super glue).
I have looked at the Thunderpants mod and it has a new thick wood baffle that is surely more rigid and wonder how much this
new baffle adds to the improved sound.
What this all boils down to is looking at mitigating resonance in one of 3 ways, you can dampen it, diffuse it or you can move it.
Time to play.